#define _CRT_SECURE_NO_WARNINGS
#pragma warning(disable:6031)

#include <stdio.h>

int main()
{
	double result = (4.5 * 2 + 4.5 * 3.1 + 3.5 * 4.3 + 3 * 3.4 + 3 * 4.1 + 4.3 + 2 * 1.3 + 4.9 * 5) / (2 + 4.5 + 3.5 + 3 + 3 + 1 + 2 + 5);
	printf("%lf", result);

	return 0;
}